The present invention relates to a liquid-supply apparatus and an image-forming system including the liquid-supply apparatus. In particular, the invention relates to an art to evacuate liquid inside a liquid-supply pan when the liquid is unnecessary.
An inkjet-recording apparatus such as a printer performs a process of applying pretreatment liquid (pretreatment) which condenses a color component of ink, in order to improve a print quality in relation to bleeding, density, color tone, show-through, and so on. The pretreatment liquid filled in the liquid-supply pan is deteriorated in an apparatus performing such a pre-application process. For example, such a pretreatment liquid is thickened or solidified thorough evaporation or contact with air. Japanese Patent Laid-open Application Publication No. 2007-050315 as Patent Document 1 discloses an art for solving such problems caused by the deterioration of the pretreatment liquid.
Patent Document 1 discloses a liquid application device in which a liquid-storage tank storing pretreatment liquid and a liquid-holding member attaching the pretreatment liquid onto a roller applying the pretreatment liquid onto paper are connected through a circulation line. The liquid application device executes a preliminary-circulation process before the liquid is applied to a recording medium of paper and so on so that the deteriorated thickening and the solid matter of the pretreatment liquid which remain in a ductwork are melted. Thereby, uneven application caused by the pretreatment liquid thickened in a flow channel or inhibition of the normal circulation can be prevented.